1. Field of the Invention
The present invention relates to a semiconductor photodetecting device and a method of manufacturing it, and more particularly to a semiconductor photodetecting device for a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) solid-state image sensor and a method of manufacturing it.
2. Description of the Related Art
CCD or MOS solid-state image sensors are mounted on digital still cameras, camcorders and the like. Such solid-state image sensors convert light incident on their semiconductor photodetecting devices which are made of semiconductor materials into electric charges. In the CCD solid-state image sensor, the generated signal charges are accumulated in potential wells, and then transferred. In the MOS solid-state image sensor, on the other hand, the generated signal charges are read out as voltage directly from the semiconductor photodetecting devices using MOS transistors. Imaging areas in those solid-state image sensors, in which the semiconductor photodetecting devices are two-dimensionally arranged, have red-green-blue (RGB) primary color filters with the Bayer or stripe type color array for colorization (for example, refer to Japanese Laid-Open Patent Application No. 05-183139 publication).
FIG. 1 is a schematic cross-sectional view showing a structure of a semiconductor photodetecting device in a conventional MOS solid-state image sensor and its periphery.
The conventional solid-state image sensor is comprised of: a plurality of semiconductor photodetecting devices 21 which are a plurality of n-type regions formed in a p-type silicon substrate 20; a color filter 22 which is placed at a light incident side of the semiconductor photodetecting devices 21; and a plurality of output amplifiers 23, which have each MOS transistor 24 so as to be connected with each semiconductor photodetecting device 21, and which convert signal charges into voltage, amplify the voltage, and output it.
It should be noted that RGB primary colors in the color filter 22 are arranged in the Bayer color array pattern as shown in FIG. 2.